diff --git a/test/test_boolean.py b/test/test_boolean.py
new file mode 100644
index 00000000..7e5402be
--- /dev/null
+++ b/test/test_boolean.py
@@ -0,0 +1,103 @@
+
+"""
+Checks that the implementation does not make use of boolean operations (==, <=, !, etc)
+in assignments or function calls.
+"""
+
+import os
+
+import pytest
+
+import helpers
+import pqclean
+import pycparser
+
+
+def setup_module():
+    if not(os.path.exists(os.path.join('pycparser', '.git'))):
+        print("Please run `git submodule update --init`")
+
+
+class ForbiddenLineVisitor(pycparser.c_ast.NodeVisitor): 
+  def __init__(self):
+    self.errors = []
+
+  def visit_Assignment(self, node): 
+    v = ForbiddenOpVisitor();
+    v.visit(node.rvalue)
+    self.errors.extend(v.errors)
+
+  def visit_FuncCall(self, node): 
+    if node.args:
+        v = ForbiddenOpVisitor();
+        v.visit(node.args)
+        self.errors.extend(v.errors)
+
+class ForbiddenOpVisitor(pycparser.c_ast.NodeVisitor): 
+  def __init__(self):
+    self.errors = []
+
+  def visit_BinaryOp(self, node): 
+    v = ForbiddenOpVisitor();
+    v.visit(node.left)
+    self.errors.extend(v.errors)
+    if node.op in ['<', '<=', '>', '>=', '==', '!=', '&&', '||']:
+      err = "\n {} at {c.file}:{c.line}:{c.column}".format(node.op, c=node.coord)
+      self.errors.append(err)
+    v = ForbiddenOpVisitor();
+    v.visit(node.right)
+    self.errors.extend(v.errors)
+
+  def visit_UnaryOp(self, node): 
+    if node.op == '!':
+      err = "\n {} at {c.file}:{c.line}:{c.column}".format(node.op, c=node.coord)
+      self.errors.append(err)
+    v = ForbiddenOpVisitor();
+    v.visit(node.expr)
+    self.errors.extend(v.errors)
+
+  def visit_TernaryOp(self, node): 
+    err = "\n ternary operator at {c.file}:{c.line}:{c.column}".format(c=node.coord)
+    self.errors.append(err)
+
+
+@pytest.mark.parametrize(
+    'implementation',
+    pqclean.Scheme.all_implementations(),
+    ids=str,
+)
+@helpers.skip_windows()
+@helpers.filtered_test
+def test_boolean(implementation):
+    errors = []
+    for fname in os.listdir(implementation.path()):
+        if not fname.endswith(".c"):
+            continue
+        tdir, _ = os.path.split(os.path.realpath(__file__))
+        ast = pycparser.parse_file(
+            os.path.join(implementation.path(), fname),
+            use_cpp=True,
+            cpp_path='cc',  # not all platforms link cpp correctly; cc -E works
+            cpp_args=[
+                '-E',
+                '-std=c99',
+                '-nostdinc',  # pycparser cannot deal with e.g. __attribute__
+                '-I{}'.format(os.path.join(tdir, "../common")),
+                # necessary to mock e.g. <stdint.h>
+                '-I{}'.format(
+                    os.path.join(tdir, 'pycparser/utils/fake_libc_include')),
+            ]
+        )
+        v = ForbiddenLineVisitor()
+        v.visit(ast)
+        errors.extend(v.errors)
+    if errors:
+        raise AssertionError(
+            "Prohibited use of boolean operations in assignment or function call" +
+            "".join(errors)
+        )
+
+
+if __name__ == "__main__":
+    import sys
+    pytest.main(sys.argv)