diff --git a/addons/cert.py b/addons/cert.py
index 34454e76a..cac9d0c26 100755
--- a/addons/cert.py
+++ b/addons/cert.py
@@ -233,6 +233,16 @@ def int31(data, platform):
                     'Ensure that integer conversions do not result in lost or misinterpreted data (casting ' + str(value.intvalue) + ' to ' + destType + ')',
                     'INT31-c')
                 break
+
+
+# ENV33-C
+# Do not call system()
+def env33(data):
+    for token in data.tokenlist:
+        if isFunctionCall(token, ('system',), 1):
+            reportError(token, 'style', 'Do not call system()', 'ENV33-C')
+
+
 # MSC24-C
 # Do not use deprecated or obsolescent functions
 def msc24(data):
@@ -399,6 +409,7 @@ if __name__ == '__main__':
             str05(cfg)
             str07(cfg)
             str11(cfg)
+            env33(cfg)
             msc24(cfg)
             msc30(cfg)
             api01(cfg)
diff --git a/addons/test/cert-test.c b/addons/test/cert-test.c
index dd850c179..64c8b6ea7 100644
--- a/addons/test/cert-test.c
+++ b/addons/test/cert-test.c
@@ -21,12 +21,12 @@ void api01()
     }
     struct good_node_s
     {
-        struct good_node_s* next;      
+        struct good_node_s* next;
         char name[String_Size];
     }
     struct also_good_node_s
     {
-        struct also_good_node_s* next;      
+        struct also_good_node_s* next;
         char *name;
     }
 }
@@ -74,12 +74,18 @@ unsigned char int31(int x)
     x = (unsigned long long)-1; // cert-INT31-c
 }
 
+void env33()
+{
+    system("chmod -x $(which chmod)"); // cert-ENV33-C
+    int system;
+}
+
 void msc24()
 {
     struct S {
     int x; int fopen;
     };
-    
+
     struct S s;
     time_t rawtime;
     struct tm *timeinfo;