diff --git a/src/libCom/macLib/macLib.h b/src/libCom/macLib/macLib.h
index 44970ff10..89dccf72c 100644
--- a/src/libCom/macLib/macLib.h
+++ b/src/libCom/macLib/macLib.h
@@ -148,7 +148,7 @@ epicsShareAPI macInstallMacros(
 
 epicsShareFunc char *           /* expanded string; NULL if any undefined macros */
 epicsShareAPI macEnvExpand(
-    const char *str            /* string to be expanded */
+    const char *str             /* string to be expanded */
 );
 
 epicsShareFunc char *           /* expanded string; NULL if any undefined macros */