diff --git a/CHANGES.current b/CHANGES.current
index 1f0dd3807..15769cbdf 100644
--- a/CHANGES.current
+++ b/CHANGES.current
@@ -7,6 +7,9 @@ the issue number to the end of the URL: https://github.com/swig/swig/issues/
 Version 4.1.0 (in progress)
 ===========================
 
+2022-07-26: olly
+            Fix incorrect operator precedence in preprocessor expressions.
+
 2022-07-20: wsfulton
             [C#, Java] Ensure the order of interfaces generated in proxy interfaces for the
             %interface family of macros is the same as that parsed from the bases in C++.
diff --git a/Examples/test-suite/common.mk b/Examples/test-suite/common.mk
index 32444688d..7626872cd 100644
--- a/Examples/test-suite/common.mk
+++ b/Examples/test-suite/common.mk
@@ -746,6 +746,7 @@ C_TEST_CASES += \
 	preproc \
 	preproc_constants_c \
 	preproc_defined \
+	preproc_expr \
 	preproc_gcc_output \
 	preproc_include \
 	preproc_line_file \
diff --git a/Examples/test-suite/preproc_expr.i b/Examples/test-suite/preproc_expr.i
new file mode 100644
index 000000000..a24f7715c
--- /dev/null
+++ b/Examples/test-suite/preproc_expr.i
@@ -0,0 +1,34 @@
+%module preproc_expr
+
+// Check expressions which suffered from incorrect operator precedence prior
+// to SWIG 4.1.0.
+
+%inline %{
+// `!` should have higher precedence than binary `+`.
+#if !0 + 1
+#else
+# error Bad preprocessor expression operator precedence
+#endif
+
+// `!=` should have higher precedence than bitwise and.
+#if 1 & 2 != 0
+#else
+# error Bad preprocessor expression operator precedence
+#endif
+
+// `==` should have higher precedence than bitwise or.
+#if (2 | 1 == 3) != 2
+# error Bad preprocessor expression operator precedence
+#endif
+
+// `!=` should have higher precedence than bitwise xor.
+#if 1 ^ 2 != 4
+# error Bad preprocessor expression operator precedence
+#endif
+
+// `<` should have higher precedence than '=='.
+#if 2 == 2 < 2
+# error Bad preprocessor expression operator precedence
+#endif
+
+%}
diff --git a/Source/Preprocessor/expr.c b/Source/Preprocessor/expr.c
index 52e467b6c..b2efba57e 100644
--- a/Source/Preprocessor/expr.c
+++ b/Source/Preprocessor/expr.c
@@ -54,6 +54,7 @@ static const char *errmsg = 0;	/* Parsing error       */
 /* Initialize the precedence table for various operators.  Low values have higher precedence */
 static void init_precedence(void) {
   prec[SWIG_TOKEN_NOT] = 10;
+  prec[SWIG_TOKEN_LNOT] = 10;
   prec[OP_UMINUS] = 10;
   prec[OP_UPLUS] = 10;
   prec[SWIG_TOKEN_STAR] = 20;
@@ -63,16 +64,15 @@ static void init_precedence(void) {
   prec[SWIG_TOKEN_MINUS] = 30;
   prec[SWIG_TOKEN_LSHIFT] = 40;
   prec[SWIG_TOKEN_RSHIFT] = 40;
-  prec[SWIG_TOKEN_AND] = 50;
-  prec[SWIG_TOKEN_XOR] = 60;
-  prec[SWIG_TOKEN_OR] = 70;
-  prec[SWIG_TOKEN_EQUALTO] = 80;
-  prec[SWIG_TOKEN_NOTEQUAL] = 80;
-  prec[SWIG_TOKEN_LESSTHAN] = 80;
-  prec[SWIG_TOKEN_GREATERTHAN] = 80;
-  prec[SWIG_TOKEN_LTEQUAL] = 80;
-  prec[SWIG_TOKEN_GTEQUAL] = 80;
-  prec[SWIG_TOKEN_LNOT] = 90;
+  prec[SWIG_TOKEN_LESSTHAN] = 50;
+  prec[SWIG_TOKEN_GREATERTHAN] = 50;
+  prec[SWIG_TOKEN_LTEQUAL] = 50;
+  prec[SWIG_TOKEN_GTEQUAL] = 50;
+  prec[SWIG_TOKEN_EQUALTO] = 60;
+  prec[SWIG_TOKEN_NOTEQUAL] = 60;
+  prec[SWIG_TOKEN_AND] = 70;
+  prec[SWIG_TOKEN_XOR] = 80;
+  prec[SWIG_TOKEN_OR] = 90;
   prec[SWIG_TOKEN_LAND] = 100;
   prec[SWIG_TOKEN_LOR] = 110;
   expr_init = 1;