diff --git a/certmanager/ConfigureChecks.cmake b/certmanager/ConfigureChecks.cmake
index 6148f056..8d8d6a25 100644
--- a/certmanager/ConfigureChecks.cmake
+++ b/certmanager/ConfigureChecks.cmake
@@ -20,5 +20,13 @@ if( _result )
   tde_message_fatal( "Unable to run getconf!\n MAX_CMD_LENGTH cannot be determined." )
 endif()
 math( EXPR MAX_CMD_LENGTH "(${MAX_CMD_LENGTH} / 4) * 3" )
+# Work around a 64 bit bug in the CMake math function above
+if( NOT MAX_CMD_LENGTH )
+  execute_process(
+    COMMAND getconf ARG_MAX
+    OUTPUT_VARIABLE MAX_CMD_LENGTH
+    RESULT_VARIABLE _result
+    OUTPUT_STRIP_TRAILING_WHITESPACE )
+endif()
 message( STATUS "  found ${MAX_CMD_LENGTH}" )
 set( MAX_CMD_LENGTH ${MAX_CMD_LENGTH} CACHE INTERNAL "" FORCE )