diff --git a/MagickCore/string.c b/MagickCore/string.c
index 9af4d3d7e3..284614b5d0 100644
--- a/MagickCore/string.c
+++ b/MagickCore/string.c
@@ -2592,7 +2592,7 @@ MagickExport MagickBooleanType SubstituteString(char **string,
   {
     if (search_extent == 0)
       search_extent=strlen(search);
-    if ((*p == *search) && (strncmp(p,search,search_extent) != 0))
+    if ((*p != *search) || (strncmp(p,search,search_extent) != 0))
       continue;
     /*
       We found a match.