diff --git a/apache2/apache2_io.c b/apache2/apache2_io.c
index ec778c3f..c82ef1c8 100644
--- a/apache2/apache2_io.c
+++ b/apache2/apache2_io.c
@@ -445,7 +445,7 @@ static int flatten_response_body(modsec_rec *msr) {
     msr->resbody_status = RESBODY_STATUS_READ_BRIGADE;
 
     if (msr->resbody_length + 1 <= 0) {
-        msr_log(msr, 1, "Output filter: Invalid response length: %lu", msr->resbody_length);
+        msr_log(msr, 1, "Output filter: Invalid response length: %" APR_SIZE_T_FMT, msr->resbody_length);
         return -1;
     }
 
diff --git a/apache2/modsecurity.h b/apache2/modsecurity.h
index 0dfcb4ae..bd4bf38f 100644
--- a/apache2/modsecurity.h
+++ b/apache2/modsecurity.h
@@ -31,7 +31,7 @@ typedef struct msc_string msc_string;
 #endif
 
 /* For GNU C, tell the compiler to check printf like formatters */
-#if defined(__GNUC__)
+#if (defined(__GNUC__) && !defined(SOLARIS2))
 #define PRINTF_ATTRIBUTE(a,b) __attribute__((format (printf, a, b)))
 #else
 #define PRINTF_ATTRIBUTE(a,b)