diff --git a/src/config.h.in b/src/config.h.in
index 520d7d6..1f3dc58 100644
--- a/src/config.h.in
+++ b/src/config.h.in
@@ -1,4 +1,4 @@
-/* config.h.in.  Generated from configure.in by autoheader.  */
+/* config.h.in.  Generated from configure.ac by autoheader.  */
 
 /* Define if the C++ compiler supports stack-allocated variable-size arrays.
    */
diff --git a/src/config.h.msvc b/src/config.h.msvc
index 520d7d6..1f3dc58 100644
--- a/src/config.h.msvc
+++ b/src/config.h.msvc
@@ -1,4 +1,4 @@
-/* config.h.in.  Generated from configure.in by autoheader.  */
+/* config.h.in.  Generated from configure.ac by autoheader.  */
 
 /* Define if the C++ compiler supports stack-allocated variable-size arrays.
    */
diff --git a/src/config.h_vms b/src/config.h_vms
index 520d7d6..1f3dc58 100644
--- a/src/config.h_vms
+++ b/src/config.h_vms
@@ -1,4 +1,4 @@
-/* config.h.in.  Generated from configure.in by autoheader.  */
+/* config.h.in.  Generated from configure.ac by autoheader.  */
 
 /* Define if the C++ compiler supports stack-allocated variable-size arrays.
    */