diff --git a/lib/content_encoding.c b/lib/content_encoding.c
index e39ac3ebad..182755d5f2 100644
--- a/lib/content_encoding.c
+++ b/lib/content_encoding.c
@@ -758,7 +758,7 @@ CURLcode Curl_build_unencoding_stack(struct Curl_easy *data,
     name = enclist;
 
     for(namelen = 0; *enclist && *enclist != ','; enclist++)
-      if(!ISSPACE(*enclist))
+      if(!ISBLANK(*enclist))
         namelen = enclist - name + 1;
 
     if(namelen) {