diff --git a/DEPENDENCIES b/DEPENDENCIES
index e62d9f47..53c1cdc6 100644
--- a/DEPENDENCIES
+++ b/DEPENDENCIES
@@ -1,5 +1,5 @@
 vendorpull https://github.com/sourcemeta/vendorpull 1dcbac42809cf87cb5b045106b863e17ad84ba02
-core https://github.com/sourcemeta/core 626949ede75fb77ac4a919a24af0ade6f776751d
+core https://github.com/sourcemeta/core 81cf10ad7243e799991e5c692cd3d4a6a6e5cc9f
 jsonbinpack https://github.com/sourcemeta/jsonbinpack abd40e41050d14d74af1fddb5c397de5cca3b13c
 blaze https://github.com/sourcemeta/blaze 53d6ba77c26e613b2803f044c2852d4441bfb0a1
 hydra https://github.com/sourcemeta/hydra af9f2c54709d620872ead0c3f8f683c15a0fa702
diff --git a/src/command_bundle.cc b/src/command_bundle.cc
index e583725f..330d72b2 100644
--- a/src/command_bundle.cc
+++ b/src/command_bundle.cc
@@ -23,7 +23,8 @@ auto sourcemeta::jsonschema::bundle(const sourcemeta::core::Options &options)
 
   const std::filesystem::path schema_path{options.positional().front()};
   const auto configuration_path{find_configuration(schema_path)};
-  const auto &configuration{read_configuration(options, configuration_path)};
+  const auto &configuration{
+      read_configuration(options, configuration_path, schema_path)};
   const auto dialect{default_dialect(options, configuration)};
   auto schema{sourcemeta::core::read_yaml_or_json(schema_path)};
 
diff --git a/src/command_compile.cc b/src/command_compile.cc
index ad926cde..b9786c51 100644
--- a/src/command_compile.cc
+++ b/src/command_compile.cc
@@ -22,7 +22,8 @@ auto sourcemeta::jsonschema::compile(const sourcemeta::core::Options &options)
 
   const auto &schema_path{options.positional().at(0)};
   const auto configuration_path{find_configuration(schema_path)};
-  const auto &configuration{read_configuration(options, configuration_path)};
+  const auto &configuration{
+      read_configuration(options, configuration_path, schema_path)};
   const auto dialect{default_dialect(options, configuration)};
 
   const auto schema{sourcemeta::core::read_yaml_or_json(schema_path)};
diff --git a/src/command_fmt.cc b/src/command_fmt.cc
index 2e505d21..447c1230 100644
--- a/src/command_fmt.cc
+++ b/src/command_fmt.cc
@@ -36,7 +36,7 @@ auto sourcemeta::jsonschema::fmt(const sourcemeta::core::Options &options)
     try {
       const auto configuration_path{find_configuration(entry.first)};
       const auto &configuration{
-          read_configuration(options, configuration_path)};
+          read_configuration(options, configuration_path, entry.first)};
       const auto dialect{default_dialect(options, configuration)};
       const auto &custom_resolver{
           resolver(options, options.contains("http"), dialect, configuration)};
diff --git a/src/command_inspect.cc b/src/command_inspect.cc
index 085532d3..c69f806d 100644
--- a/src/command_inspect.cc
+++ b/src/command_inspect.cc
@@ -157,7 +157,8 @@ auto sourcemeta::jsonschema::inspect(const sourcemeta::core::Options &options)
       sourcemeta::core::read_yaml_or_json(schema_path, std::ref(positions))};
 
   const auto configuration_path{find_configuration(schema_path)};
-  const auto &configuration{read_configuration(options, configuration_path)};
+  const auto &configuration{
+      read_configuration(options, configuration_path, schema_path)};
   const auto dialect{default_dialect(options, configuration)};
 
   sourcemeta::core::SchemaFrame frame{
diff --git a/src/command_lint.cc b/src/command_lint.cc
index 4bfc313b..15ed7546 100644
--- a/src/command_lint.cc
+++ b/src/command_lint.cc
@@ -196,7 +196,7 @@ auto sourcemeta::jsonschema::lint(const sourcemeta::core::Options &options)
     for (const auto &entry : for_each_json(options)) {
       const auto configuration_path{find_configuration(entry.first)};
       const auto &configuration{
-          read_configuration(options, configuration_path)};
+          read_configuration(options, configuration_path, entry.first)};
       const auto dialect{default_dialect(options, configuration)};
 
       const auto &custom_resolver{
@@ -255,7 +255,7 @@ auto sourcemeta::jsonschema::lint(const sourcemeta::core::Options &options)
     for (const auto &entry : for_each_json(options)) {
       const auto configuration_path{find_configuration(entry.first)};
       const auto &configuration{
-          read_configuration(options, configuration_path)};
+          read_configuration(options, configuration_path, entry.first)};
       const auto dialect{default_dialect(options, configuration)};
       const auto &custom_resolver{
           resolver(options, options.contains("http"), dialect, configuration)};
diff --git a/src/command_metaschema.cc b/src/command_metaschema.cc
index 7defa8d0..e45e8869 100644
--- a/src/command_metaschema.cc
+++ b/src/command_metaschema.cc
@@ -36,7 +36,8 @@ auto sourcemeta::jsonschema::metaschema(
     }
 
     const auto configuration_path{find_configuration(entry.first)};
-    const auto &configuration{read_configuration(options, configuration_path)};
+    const auto &configuration{
+        read_configuration(options, configuration_path, entry.first)};
     const auto default_dialect_option{default_dialect(options, configuration)};
 
     const auto &custom_resolver{resolver(options, options.contains("http"),
diff --git a/src/command_validate.cc b/src/command_validate.cc
index 812254e2..54ee82bd 100644
--- a/src/command_validate.cc
+++ b/src/command_validate.cc
@@ -149,7 +149,8 @@ auto sourcemeta::jsonschema::validate(const sourcemeta::core::Options &options)
   }
 
   const auto configuration_path{find_configuration(schema_path)};
-  const auto &configuration{read_configuration(options, configuration_path)};
+  const auto &configuration{
+      read_configuration(options, configuration_path, schema_path)};
   const auto dialect{default_dialect(options, configuration)};
 
   const auto schema{sourcemeta::core::read_yaml_or_json(schema_path)};
diff --git a/src/configuration.h b/src/configuration.h
index 09062ee5..36542995 100644
--- a/src/configuration.h
+++ b/src/configuration.h
@@ -21,7 +21,8 @@ inline auto find_configuration(const std::filesystem::path &path)
 
 inline auto read_configuration(
     const sourcemeta::core::Options &options,
-    const std::optional<std::filesystem::path> &configuration_path)
+    const std::optional<std::filesystem::path> &configuration_path,
+    const std::optional<std::filesystem::path> &schema_path = std::nullopt)
     -> const std::optional<sourcemeta::core::SchemaConfig> & {
   using CacheKey = std::optional<std::filesystem::path>;
   static std::map<CacheKey, std::optional<sourcemeta::core::SchemaConfig>>
@@ -48,6 +49,17 @@ inline auto read_configuration(
       throw FileError<sourcemeta::core::SchemaConfigParseError>(
           configuration_path.value(), error);
     }
+
+    assert(result.has_value());
+    if (schema_path.has_value() &&
+        !result.value().applies_to(schema_path.value())) {
+      LOG_VERBOSE(options)
+          << "Ignoring configuration file given extensions mismatch: "
+          << sourcemeta::core::weakly_canonical(configuration_path.value())
+                 .string()
+          << "\n";
+      result = std::nullopt;
+    }
   }
 
   auto [inserted_iterator, inserted] =
diff --git a/src/input.h b/src/input.h
index 2e4882fe..0ef76d1b 100644
--- a/src/input.h
+++ b/src/input.h
@@ -156,6 +156,7 @@ inline auto for_each_json(const std::vector<std::string_view> &arguments,
     const auto configuration_path{find_configuration(current_path)};
     const auto &configuration{read_configuration(options, configuration_path)};
     const auto extensions{parse_extensions(options, configuration)};
+
     handle_json_entry(configuration.has_value()
                           ? configuration.value().absolute_path
                           : current_path,
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 2f767185..8e6705f9 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -167,6 +167,7 @@ add_jsonschema_test_unix(validate/fail_benchmark_directory)
 add_jsonschema_test_unix(validate/pass_benchmark_loop)
 add_jsonschema_test_unix(validate/pass_benchmark_loop_jsonl)
 add_jsonschema_test_unix(validate/fail_benchmark_zero)
+add_jsonschema_test_unix(validate/fail_default_dialect_config_extension_mismatch)
 add_jsonschema_test_unix(validate/pass_resolve_remap)
 add_jsonschema_test_unix(validate/pass_resolve_remap_relative)
 
@@ -178,6 +179,7 @@ add_jsonschema_test_unix(metaschema/fail_single)
 add_jsonschema_test_unix(metaschema/fail_yaml)
 add_jsonschema_test_unix(metaschema/fail_non_schema)
 add_jsonschema_test_unix(metaschema/fail_no_dialect)
+add_jsonschema_test_unix(metaschema/fail_default_dialect_config_extension_mismatch)
 add_jsonschema_test_unix(metaschema/pass_cwd)
 add_jsonschema_test_unix(metaschema/pass_single)
 add_jsonschema_test_unix(metaschema/pass_2020_12)
@@ -267,6 +269,7 @@ add_jsonschema_test_unix(bundle/fail_resolve_duplicate)
 add_jsonschema_test_unix(bundle/fail_resolve_invalid_json)
 add_jsonschema_test_unix(bundle/fail_schema_invalid_json)
 add_jsonschema_test_unix(bundle/fail_unknown_metaschema)
+add_jsonschema_test_unix(bundle/fail_default_dialect_config_extension_mismatch)
 add_jsonschema_test_unix(bundle/pass_bigint)
 add_jsonschema_test_unix(bundle/pass_resolve_default_dialect_config)
 add_jsonschema_test_unix(bundle/pass_resolve_default_dialect_config_relative)
@@ -285,6 +288,7 @@ add_jsonschema_test_unix(inspect/pass_json_output)
 add_jsonschema_test_unix(inspect/fail_no_schema)
 add_jsonschema_test_unix(inspect/fail_schema_invalid_json)
 add_jsonschema_test_unix(inspect/fail_unknown_metaschema)
+add_jsonschema_test_unix(inspect/fail_default_dialect_config_extension_mismatch)
 add_jsonschema_test_unix(inspect/fail_relative_file_metaschema_ref)
 
 # Compile
@@ -300,6 +304,7 @@ add_jsonschema_test_unix(compile/pass_yaml)
 add_jsonschema_test_unix(compile/fail_no_schema)
 add_jsonschema_test_unix(compile/fail_schema_invalid_json)
 add_jsonschema_test_unix(compile/fail_unknown_metaschema)
+add_jsonschema_test_unix(compile/fail_default_dialect_config_extension_mismatch)
 add_jsonschema_test_unix(compile/pass_resolve_remap)
 add_jsonschema_test_unix(compile/pass_resolve_remap_relative)
 
diff --git a/test/bundle/fail_default_dialect_config_extension_mismatch.sh b/test/bundle/fail_default_dialect_config_extension_mismatch.sh
new file mode 100755
index 00000000..44f4369e
--- /dev/null
+++ b/test/bundle/fail_default_dialect_config_extension_mismatch.sh
@@ -0,0 +1,48 @@
+#!/bin/sh
+
+set -o errexit
+set -o nounset
+
+TMP="$(mktemp -d)"
+clean() { rm -rf "$TMP"; }
+trap clean EXIT
+
+cat << 'EOF' > "$TMP/document.json"
+{ "foo": 1 }
+EOF
+
+cat << 'EOF' > "$TMP/jsonschema.json"
+{
+  "extension": [".schema.json"],
+  "defaultDialect": "https://json-schema.org/draft/2020-12/schema"
+}
+EOF
+
+"$1" bundle "$TMP/document.json" --verbose 2>"$TMP/stderr.txt" && CODE="$?" || CODE="$?"
+test "$CODE" = "1" || exit 1
+
+cat << EOF > "$TMP/expected.txt"
+Using configuration file: $(realpath "$TMP")/jsonschema.json
+Ignoring configuration file given extensions mismatch: $(realpath "$TMP")/jsonschema.json
+error: Could not determine the base dialect of the schema
+  at file path $(realpath "$TMP")/document.json
+
+Are you sure the input is a valid JSON Schema and its base dialect is known?
+If the input does not declare the \`\$schema\` keyword, you might want to
+explicitly declare a default dialect using \`--default-dialect/-d\`
+EOF
+
+diff "$TMP/stderr.txt" "$TMP/expected.txt"
+
+# JSON error
+"$1" bundle "$TMP/document.json" --json >"$TMP/stdout.txt" && CODE="$?" || CODE="$?"
+test "$CODE" = "1" || exit 1
+
+cat << EOF > "$TMP/expected.txt"
+{
+  "error": "Could not determine the base dialect of the schema",
+  "filePath": "$(realpath "$TMP")/document.json"
+}
+EOF
+
+diff "$TMP/stdout.txt" "$TMP/expected.txt"
diff --git a/test/compile/fail_default_dialect_config_extension_mismatch.sh b/test/compile/fail_default_dialect_config_extension_mismatch.sh
new file mode 100755
index 00000000..114d23dd
--- /dev/null
+++ b/test/compile/fail_default_dialect_config_extension_mismatch.sh
@@ -0,0 +1,48 @@
+#!/bin/sh
+
+set -o errexit
+set -o nounset
+
+TMP="$(mktemp -d)"
+clean() { rm -rf "$TMP"; }
+trap clean EXIT
+
+cat << 'EOF' > "$TMP/document.json"
+{ "foo": 1 }
+EOF
+
+cat << 'EOF' > "$TMP/jsonschema.json"
+{
+  "extension": [".schema.json"],
+  "defaultDialect": "https://json-schema.org/draft/2020-12/schema"
+}
+EOF
+
+"$1" compile "$TMP/document.json" --verbose 2>"$TMP/stderr.txt" && CODE="$?" || CODE="$?"
+test "$CODE" = "1" || exit 1
+
+cat << EOF > "$TMP/expected.txt"
+Using configuration file: $(realpath "$TMP")/jsonschema.json
+Ignoring configuration file given extensions mismatch: $(realpath "$TMP")/jsonschema.json
+error: Could not determine the base dialect of the schema
+  at file path $(realpath "$TMP")/document.json
+
+Are you sure the input is a valid JSON Schema and its base dialect is known?
+If the input does not declare the \`\$schema\` keyword, you might want to
+explicitly declare a default dialect using \`--default-dialect/-d\`
+EOF
+
+diff "$TMP/stderr.txt" "$TMP/expected.txt"
+
+# JSON error
+"$1" compile "$TMP/document.json" --json >"$TMP/stdout.txt" && CODE="$?" || CODE="$?"
+test "$CODE" = "1" || exit 1
+
+cat << EOF > "$TMP/expected.txt"
+{
+  "error": "Could not determine the base dialect of the schema",
+  "filePath": "$(realpath "$TMP")/document.json"
+}
+EOF
+
+diff "$TMP/stdout.txt" "$TMP/expected.txt"
diff --git a/test/inspect/fail_default_dialect_config_extension_mismatch.sh b/test/inspect/fail_default_dialect_config_extension_mismatch.sh
new file mode 100755
index 00000000..ccd5eb73
--- /dev/null
+++ b/test/inspect/fail_default_dialect_config_extension_mismatch.sh
@@ -0,0 +1,48 @@
+#!/bin/sh
+
+set -o errexit
+set -o nounset
+
+TMP="$(mktemp -d)"
+clean() { rm -rf "$TMP"; }
+trap clean EXIT
+
+cat << 'EOF' > "$TMP/document.json"
+{ "foo": 1 }
+EOF
+
+cat << 'EOF' > "$TMP/jsonschema.json"
+{
+  "extension": [".schema.json"],
+  "defaultDialect": "https://json-schema.org/draft/2020-12/schema"
+}
+EOF
+
+"$1" inspect "$TMP/document.json" --verbose 2>"$TMP/stderr.txt" && CODE="$?" || CODE="$?"
+test "$CODE" = "1" || exit 1
+
+cat << EOF > "$TMP/expected.txt"
+Using configuration file: $(realpath "$TMP")/jsonschema.json
+Ignoring configuration file given extensions mismatch: $(realpath "$TMP")/jsonschema.json
+error: Could not determine the base dialect of the schema
+  at file path $(realpath "$TMP")/document.json
+
+Are you sure the input is a valid JSON Schema and its base dialect is known?
+If the input does not declare the \`\$schema\` keyword, you might want to
+explicitly declare a default dialect using \`--default-dialect/-d\`
+EOF
+
+diff "$TMP/stderr.txt" "$TMP/expected.txt"
+
+# JSON error
+"$1" inspect "$TMP/document.json" --json >"$TMP/stdout.txt" && CODE="$?" || CODE="$?"
+test "$CODE" = "1" || exit 1
+
+cat << EOF > "$TMP/expected.txt"
+{
+  "error": "Could not determine the base dialect of the schema",
+  "filePath": "$(realpath "$TMP")/document.json"
+}
+EOF
+
+diff "$TMP/stdout.txt" "$TMP/expected.txt"
diff --git a/test/metaschema/fail_default_dialect_config_extension_mismatch.sh b/test/metaschema/fail_default_dialect_config_extension_mismatch.sh
new file mode 100755
index 00000000..1f92d7bb
--- /dev/null
+++ b/test/metaschema/fail_default_dialect_config_extension_mismatch.sh
@@ -0,0 +1,48 @@
+#!/bin/sh
+
+set -o errexit
+set -o nounset
+
+TMP="$(mktemp -d)"
+clean() { rm -rf "$TMP"; }
+trap clean EXIT
+
+cat << 'EOF' > "$TMP/document.json"
+{ "foo": 1 }
+EOF
+
+cat << 'EOF' > "$TMP/jsonschema.json"
+{
+  "extension": [".schema.json"],
+  "defaultDialect": "https://json-schema.org/draft/2020-12/schema"
+}
+EOF
+
+"$1" metaschema "$TMP/document.json" --verbose 2>"$TMP/stderr.txt" && CODE="$?" || CODE="$?"
+test "$CODE" = "1" || exit 1
+
+cat << EOF > "$TMP/expected.txt"
+Using configuration file: $(realpath "$TMP")/jsonschema.json
+Ignoring configuration file given extensions mismatch: $(realpath "$TMP")/jsonschema.json
+error: Could not determine the base dialect of the schema
+  at file path $(realpath "$TMP/document.json")
+
+Are you sure the input is a valid JSON Schema and its base dialect is known?
+If the input does not declare the \`\$schema\` keyword, you might want to
+explicitly declare a default dialect using \`--default-dialect/-d\`
+EOF
+
+diff "$TMP/stderr.txt" "$TMP/expected.txt"
+
+# JSON error
+"$1" metaschema "$TMP/document.json" --json >"$TMP/stdout.txt" && CODE="$?" || CODE="$?"
+test "$CODE" = "1" || exit 1
+
+cat << EOF > "$TMP/expected.txt"
+{
+  "error": "Could not determine the base dialect of the schema",
+  "filePath": "$(realpath "$TMP/document.json")"
+}
+EOF
+
+diff "$TMP/stdout.txt" "$TMP/expected.txt"
diff --git a/test/validate/fail_default_dialect_config_extension_mismatch.sh b/test/validate/fail_default_dialect_config_extension_mismatch.sh
new file mode 100755
index 00000000..3e36973f
--- /dev/null
+++ b/test/validate/fail_default_dialect_config_extension_mismatch.sh
@@ -0,0 +1,54 @@
+#!/bin/sh
+
+set -o errexit
+set -o nounset
+
+TMP="$(mktemp -d)"
+clean() { rm -rf "$TMP"; }
+trap clean EXIT
+
+cat << 'EOF' > "$TMP/document.json"
+{ "foo": 1 }
+EOF
+
+cat << 'EOF' > "$TMP/instance.json"
+{ "bar": 2 }
+EOF
+
+cat << 'EOF' > "$TMP/jsonschema.json"
+{
+  "extension": [".schema.json"],
+  "defaultDialect": "https://json-schema.org/draft/2020-12/schema"
+}
+EOF
+
+"$1" validate "$TMP/document.json" "$TMP/instance.json" --verbose 2>"$TMP/stderr.txt" \
+  && CODE="$?" || CODE="$?"
+test "$CODE" = "1" || exit 1
+
+cat << EOF > "$TMP/expected.txt"
+Using configuration file: $(realpath "$TMP")/jsonschema.json
+Ignoring configuration file given extensions mismatch: $(realpath "$TMP")/jsonschema.json
+error: Could not determine the base dialect of the schema
+  at file path $(realpath "$TMP")/document.json
+
+Are you sure the input is a valid JSON Schema and its base dialect is known?
+If the input does not declare the \`\$schema\` keyword, you might want to
+explicitly declare a default dialect using \`--default-dialect/-d\`
+EOF
+
+diff "$TMP/stderr.txt" "$TMP/expected.txt"
+
+# JSON error
+"$1" validate "$TMP/document.json" "$TMP/instance.json" --json >"$TMP/stdout.txt" \
+  && CODE="$?" || CODE="$?"
+test "$CODE" = "1" || exit 1
+
+cat << EOF > "$TMP/expected.txt"
+{
+  "error": "Could not determine the base dialect of the schema",
+  "filePath": "$(realpath "$TMP")/document.json"
+}
+EOF
+
+diff "$TMP/stdout.txt" "$TMP/expected.txt"
diff --git a/vendor/core/src/extension/schemaconfig/CMakeLists.txt b/vendor/core/src/extension/schemaconfig/CMakeLists.txt
index 44423676..d27f4190 100644
--- a/vendor/core/src/extension/schemaconfig/CMakeLists.txt
+++ b/vendor/core/src/extension/schemaconfig/CMakeLists.txt
@@ -1,5 +1,5 @@
 sourcemeta_library(NAMESPACE sourcemeta PROJECT core NAME schemaconfig
-  PRIVATE_HEADERS error.h SOURCES parse.cc find.cc)
+  PRIVATE_HEADERS error.h SOURCES parse.cc schemaconfig.cc)
 
 if(SOURCEMETA_CORE_INSTALL)
   sourcemeta_library_install(NAMESPACE sourcemeta PROJECT core NAME schemaconfig)
diff --git a/vendor/core/src/extension/schemaconfig/include/sourcemeta/core/schemaconfig.h b/vendor/core/src/extension/schemaconfig/include/sourcemeta/core/schemaconfig.h
index 8ae6bda6..ade4e89a 100644
--- a/vendor/core/src/extension/schemaconfig/include/sourcemeta/core/schemaconfig.h
+++ b/vendor/core/src/extension/schemaconfig/include/sourcemeta/core/schemaconfig.h
@@ -49,6 +49,11 @@ struct SOURCEMETA_CORE_SCHEMACONFIG_EXPORT SchemaConfig {
   std::unordered_map<JSON::String, JSON::String> resolve;
   JSON extra = JSON::make_object();
 
+  /// Check if the given path represents a schema described by this
+  /// configuration
+  [[nodiscard]]
+  auto applies_to(const std::filesystem::path &path) const -> bool;
+
   /// Parse a configuration file from its contents
   [[nodiscard]]
   static auto from_json(const JSON &value,
diff --git a/vendor/core/src/extension/schemaconfig/find.cc b/vendor/core/src/extension/schemaconfig/schemaconfig.cc
similarity index 69%
rename from vendor/core/src/extension/schemaconfig/find.cc
rename to vendor/core/src/extension/schemaconfig/schemaconfig.cc
index 717227f2..4a428d2c 100644
--- a/vendor/core/src/extension/schemaconfig/find.cc
+++ b/vendor/core/src/extension/schemaconfig/schemaconfig.cc
@@ -1,7 +1,9 @@
 #include <sourcemeta/core/io.h>
 #include <sourcemeta/core/schemaconfig.h>
 
-#include <cassert> // assert
+#include <algorithm> // std::ranges::any_of
+#include <cassert>   // assert
+#include <string>    // std::string
 
 namespace sourcemeta::core {
 
@@ -31,4 +33,11 @@ auto SchemaConfig::find(const std::filesystem::path &path)
   return std::nullopt;
 }
 
+auto SchemaConfig::applies_to(const std::filesystem::path &path) const -> bool {
+  const std::string filename{path.filename().string()};
+  return std::ranges::any_of(this->extension, [&filename](const auto &suffix) {
+    return filename.ends_with(suffix);
+  });
+}
+
 } // namespace sourcemeta::core