diff --git a/ChangeLog b/ChangeLog
index 2cbadf9e9..e25c9430f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2012-01-13  Robert Larice
+ * src/include/ngspice/missing_math.h :
+  revert last commit, simply insane
+    checking for being a macro is already done with HAVE_DECL_ISNAN
+
 2012-01-11  Robert Larice
  * src/include/ngspice/missing_math.h :
   wrap isnan declaration, isnan is a macro on modern systems
diff --git a/src/include/ngspice/missing_math.h b/src/include/ngspice/missing_math.h
index be4d59894..0ab551e47 100644
--- a/src/include/ngspice/missing_math.h
+++ b/src/include/ngspice/missing_math.h
@@ -26,7 +26,7 @@ extern double scalbn(double, int);
 #endif
 
 #if !HAVE_DECL_ISNAN
-#if !defined(HAVE_ISNAN) && !defined(isnan)
+#ifndef HAVE_ISNAN
 extern int isnan(double);
 #endif
 #endif