diff --git a/src/mk-file-embed.pl b/src/mk-file-embed.pl
index 3447aa9472..e4dbe35de1 100755
--- a/src/mk-file-embed.pl
+++ b/src/mk-file-embed.pl
@@ -29,11 +29,16 @@ if($ARGV[0] eq "--var") {
     $varname = shift @ARGV;
 }
 
+my $varname_upper = uc($varname);
+
 print <<HEAD
 /*
  * NEVER EVER edit this manually, fix the mk-file-embed.pl script instead!
  */
+#ifndef CURL_DECLARED_${varname_upper}
+#define CURL_DECLARED_${varname_upper}
 extern const unsigned char ${varname}[];
+#endif
 const unsigned char ${varname}[] = {
 HEAD
     ;
diff --git a/src/tool_operate.c b/src/tool_operate.c
index ed5ab4d6c8..5aadf26d23 100644
--- a/src/tool_operate.c
+++ b/src/tool_operate.c
@@ -105,8 +105,11 @@ CURL_EXTERN CURLcode curl_easy_perform_ev(CURL *easy);
 #include "memdebug.h" /* keep this as LAST include */
 
 #ifdef CURL_CA_EMBED
+#ifndef CURL_DECLARED_CURL_CA_EMBED
+#define CURL_DECLARED_CURL_CA_EMBED
 extern const unsigned char curl_ca_embed[];
 #endif
+#endif
 
 #ifndef O_BINARY
 /* since O_BINARY as used in bitmasks, setting it to zero makes it usable in
