diff --git a/CHANGELOG b/CHANGELOG
index bd139c1..9719834 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -2,8 +2,8 @@
 - Improve error reporting
 - Release is now signed with PGP
 - Doesn't crash on network errors
-- Fixed optimization introduced in 2.2
-  that did not hold in all cases.
+- Fixed optimization introduced in 2.2 that did not hold in all cases
+- Better handling of parenthesis inside string literals
 
 2.3
 - Very small release. The windows setup now installs the C++ library
diff --git a/relational/parser.py b/relational/parser.py
index e351d8c..187cb8d 100644
--- a/relational/parser.py
+++ b/relational/parser.py
@@ -291,7 +291,21 @@ def _find_matching_parenthesis(expression, start=0, openpar=u'(', closepar=u')')
     close parenthesis to the 1st open parenthesis found
     starting from start (0 by default)'''
     par_count = 0  # Count of parenthesis
+
+    string = False
+    escape = False
+
     for i in range(start, len(expression)):
+        if expression[i] == '\'' and not escape:
+            string = not string
+        if expression[i] == '\\' and not escape:
+            escape = True
+        else:
+            escape = False
+        if string:
+            continue
+
+
         if expression[i] == openpar:
             par_count += 1
         elif expression[i] == closepar:
@@ -299,6 +313,30 @@ def _find_matching_parenthesis(expression, start=0, openpar=u'(', closepar=u')')
             if par_count == 0:
                 return i  # Closing parenthesis of the parameter
 
+def _find_token(haystack, needle):
+    '''
+    Like the string function find, but
+    ignores tokens that are within a string
+    literal.
+    '''
+    r = -1
+    string = False
+    escape = False
+
+    for i in range(len(haystack)):
+        if haystack[i] == '\'' and not escape:
+            string = not string
+        if haystack[i] == '\\' and not escape:
+            escape = True
+        else:
+            escape = False
+        if string:
+            continue
+
+        if haystack[i:].startswith(needle):
+            return i
+    return r
+
 
 def tokenize(expression):
     '''This function converts a relational expression into a list where
@@ -331,7 +369,7 @@ def tokenize(expression):
                 par = expression.find(
                     '(', _find_matching_parenthesis(expression))
             else:  # Expression without parenthesis, so adding what's between start and parenthesis as whole
-                par = expression.find('(')
+                par = _find_token(expression, '(')
 
             items.append(expression[:par].strip())
                          # Inserting parameter of the operator
diff --git a/test/par1.query b/test/par1.query
new file mode 100644
index 0000000..c0aca14
--- /dev/null
+++ b/test/par1.query
@@ -0,0 +1 @@
+σ name=='(' (people)
diff --git a/test/par1.result b/test/par1.result
new file mode 100644
index 0000000..9d637aa
--- /dev/null
+++ b/test/par1.result
@@ -0,0 +1 @@
+id,name,chief,age
diff --git a/test/par2.query b/test/par2.query
new file mode 100644
index 0000000..5570f40
--- /dev/null
+++ b/test/par2.query
@@ -0,0 +1 @@
+σ (name=='(') (people)
diff --git a/test/par2.result b/test/par2.result
new file mode 100644
index 0000000..9d637aa
--- /dev/null
+++ b/test/par2.result
@@ -0,0 +1 @@
+id,name,chief,age
diff --git a/test/par3.query b/test/par3.query
new file mode 100644
index 0000000..117f61f
--- /dev/null
+++ b/test/par3.query
@@ -0,0 +1 @@
+σ (name==')') (people)
diff --git a/test/par3.result b/test/par3.result
new file mode 100644
index 0000000..9d637aa
--- /dev/null
+++ b/test/par3.result
@@ -0,0 +1 @@
+id,name,chief,age
diff --git a/test/par4.query b/test/par4.query
new file mode 100644
index 0000000..6d8045f
--- /dev/null
+++ b/test/par4.query
@@ -0,0 +1 @@
+σ name==')' (people)
diff --git a/test/par4.result b/test/par4.result
new file mode 100644
index 0000000..9d637aa
--- /dev/null
+++ b/test/par4.result
@@ -0,0 +1 @@
+id,name,chief,age