diff --git a/src/template.c b/src/template.c
index 1e9a77feb223..7eb7d811ca4c 100644
--- a/src/template.c
+++ b/src/template.c
@@ -1540,7 +1540,7 @@ MATCH TemplateDeclaration::deduceFunctionTemplateMatch(
                                  * the oded == oarg
                                  */
                                 (*dedargs)[i] = oded;
-                                MATCH m2 = tparam->matchArg(loc, paramscope, dedargs, i, parameters, dedtypes, NULL);
+                                MATCH m2 = tparam->matchArg(instLoc, paramscope, dedargs, i, parameters, dedtypes, NULL);
                                 //printf("m2 = %d\n", m2);
                                 if (m2 <= MATCHnomatch)
                                     goto Lnomatch;
@@ -1558,7 +1558,7 @@ MATCH TemplateDeclaration::deduceFunctionTemplateMatch(
                         }
                         else
                         {
-                            oded = tparam->defaultArg(loc, paramscope);
+                            oded = tparam->defaultArg(instLoc, paramscope);
                             if (oded)
                                 (*dedargs)[i] = declareParameter(paramscope, tparam, oded);
                         }
diff --git a/test/compilable/test15668.d b/test/compilable/test15668.d
new file mode 100644
index 000000000000..723521622001
--- /dev/null
+++ b/test/compilable/test15668.d
@@ -0,0 +1,9 @@
+void foo ( int line = __LINE__ ) ( string msg = "" )
+{
+    static assert (line == 8);
+}
+
+void main()
+{
+    foo();
+}