diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index bfa87e6..35b997d 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -24,7 +24,7 @@ jobs:
       - run: mv zig-out/lib/libfastfec.so libfastfec-linux-x86_64-${{ steps.get_version.outputs.VERSION }}.so
       - run: zig build -Dlib-only=true -Dtarget=aarch64-linux
       - run: mv zig-out/lib/libfastfec.so libfastfec-linux-aarch64-${{ steps.get_version.outputs.VERSION }}.so
-      - run: zig build -Dlib-only=true -Dtarget=wasm32-freestanding
+      - run: zig build -Dwasm
       - run: mv zig-out/lib/fastfec.wasm libfastfec-${{ steps.get_version.outputs.VERSION }}.wasm
       - name: Release
         uses: softprops/action-gh-release@v1
diff --git a/build.zig b/build.zig
index 01caa2b..a90718b 100644
--- a/build.zig
+++ b/build.zig
@@ -1,5 +1,6 @@
 const std = @import("std");
 const builtin = @import("builtin");
+const CrossTarget = std.zig.CrossTarget;
 
 pub fn build(b: *std.build.Builder) !void {
     b.setPreferredReleaseMode(.ReleaseFast);
@@ -7,17 +8,17 @@ pub fn build(b: *std.build.Builder) !void {
     const mode = b.standardReleaseOptions();
 
     const lib_only: bool = b.option(bool, "lib-only", "Only compile the library") orelse false;
+    const wasm: bool = b.option(bool, "wasm", "Compile the wasm library") orelse false;
 
     // Compile pcre
     const pcre = b.addStaticLibrary("pcre", null);
-    pcre.setBuildMode(.ReleaseFast);
     pcre.setTarget(target);
     pcre.linkLibC();
     pcre.addIncludeDir(pcreIncludeDir);
     pcre.addCSourceFiles(&pcreSources, &buildOptions);
 
     // Main build step
-    if (!lib_only) {
+    if (!lib_only and !wasm) {
         const fastfec_cli = b.addExecutable("fastfec", null);
         fastfec_cli.setTarget(target);
         fastfec_cli.setBuildMode(mode);
@@ -45,18 +46,34 @@ pub fn build(b: *std.build.Builder) !void {
         }, &buildOptions);
     }
 
-    // Library build step
-    const fastfec_lib = b.addSharedLibrary("fastfec", null, .unversioned);
-    fastfec_lib.setTarget(target);
-    fastfec_lib.setBuildMode(mode);
-    fastfec_lib.install();
-    fastfec_lib.linkLibC();
-    fastfec_lib.addCSourceFiles(&libSources, &buildOptions);
-    if (builtin.os.tag == .windows) {
-        fastfec_lib.linkSystemLibrary("pcre");
+    if (!wasm) {
+        // Library build step
+        const fastfec_lib = b.addSharedLibrary("fastfec", null, .unversioned);
+        fastfec_lib.setTarget(target);
+        fastfec_lib.setBuildMode(mode);
+        fastfec_lib.install();
+        fastfec_lib.linkLibC();
+        if (builtin.os.tag == .windows) {
+            fastfec_lib.linkSystemLibrary("pcre");
+        } else {
+            fastfec_lib.addIncludeDir(pcreIncludeDir);
+            fastfec_lib.linkLibrary(pcre);
+        }
+        fastfec_lib.addCSourceFiles(&libSources, &buildOptions);
     } else {
-        fastfec_lib.addIncludeDir(pcreIncludeDir);
-        fastfec_lib.linkLibrary(pcre);
+        // Wasm library build step
+        const fastfec_wasm = b.addSharedLibrary("fastfec", null, .unversioned);
+        const wasm_target = CrossTarget{ .cpu_arch = .wasm32, .os_tag = .wasi };
+        fastfec_wasm.setTarget(wasm_target);
+        // Update pcre target for wasm
+        pcre.setTarget(wasm_target);
+        fastfec_wasm.setBuildMode(mode);
+        fastfec_wasm.install();
+        fastfec_wasm.linkLibC();
+        fastfec_wasm.addIncludeDir(pcreIncludeDir);
+        fastfec_wasm.linkLibrary(pcre);
+        fastfec_wasm.addCSourceFiles(&libSources, &buildOptions);
+        fastfec_wasm.addCSourceFile("src/wasm.c", &buildOptions);
     }
 
     // Test step
diff --git a/python/fastfec.py b/python/fastfec.py
index 5678bac..dabe403 100644
--- a/python/fastfec.py
+++ b/python/fastfec.py
@@ -49,7 +49,7 @@ def init_lib(self):
         self.libfastfec = CDLL(os.path.join(SCRIPT_DIR, "../zig-out/lib/libfastfec.dylib"))
 
         # Lay out arg/res types
-        self.libfastfec.newPersistentMemoryContext.argtypes = [c_int]
+        self.libfastfec.newPersistentMemoryContext.argtypes = []
         self.libfastfec.newPersistentMemoryContext.restype = c_void_p
 
         self.libfastfec.newFecContext.argtypes = [
diff --git a/src/main.c b/src/main.c
index 28c8c26..e772dc4 100644
--- a/src/main.c
+++ b/src/main.c
@@ -279,7 +279,7 @@ int main(int argc, char *argv[])
   }
 
   // Initialize persistent memory context
-  PERSISTENT_MEMORY_CONTEXT *persistentMemory = newPersistentMemoryContext(0);
+  PERSISTENT_MEMORY_CONTEXT *persistentMemory = newPersistentMemoryContext();
   // Initialize FEC context
   FEC_CONTEXT *fec = newFecContext(persistentMemory, ((BufferRead)(&url_readBuffer)), BUFFERSIZE, NULL, BUFFERSIZE, handle, fecId, outputDirectory, includeFilingId, silent, warn);
 
diff --git a/src/memory.c b/src/memory.c
index 2b85359..519cb6f 100644
--- a/src/memory.c
+++ b/src/memory.c
@@ -68,7 +68,7 @@ void copyString(STRING *src, STRING *dst)
   strcpy(dst->str, src->str);
 }
 
-PERSISTENT_MEMORY_CONTEXT *newPersistentMemoryContext(int bufferSize)
+PERSISTENT_MEMORY_CONTEXT *newPersistentMemoryContext()
 {
   PERSISTENT_MEMORY_CONTEXT *ctx = malloc(sizeof(PERSISTENT_MEMORY_CONTEXT));
   ctx->rawLine = newString(DEFAULT_STRING_SIZE);
diff --git a/src/wasm.c b/src/wasm.c
new file mode 100644
index 0000000..4100933
--- /dev/null
+++ b/src/wasm.c
@@ -0,0 +1,12 @@
+#include "fec.h"
+
+extern size_t wasmBufferRead(char *buffer, int want, void *data);
+extern void wasmBufferWrite(char* filename, char* extension, char* contents, int numBytes);
+
+void wasmFec(int bufferSize) {
+  PERSISTENT_MEMORY_CONTEXT *persistentMemory = newPersistentMemoryContext();
+  FEC_CONTEXT *fec = newFecContext(persistentMemory, ((BufferRead)(&wasmBufferRead)), bufferSize, ((CustomWriteFunction)(&wasmBufferWrite)), bufferSize, NULL, NULL, NULL, 0, 1, 0);
+  int fecParseResult = parseFec(fec);
+  freeFecContext(fec);
+  freePersistentMemoryContext(persistentMemory);
+}