diff --git a/lib/preprocessor.cpp b/lib/preprocessor.cpp
index 752e57b8c..129b1dcb4 100644
--- a/lib/preprocessor.cpp
+++ b/lib/preprocessor.cpp
@@ -2776,11 +2776,14 @@ public:
                         continue;
                     }
                     optcomma = false;
+                    // separate ++ and -- with space
+                    if (!str.empty() && !macrocode.empty() && (str[0] == '+' || str[0] == '-') && str[0] == macrocode[macrocode.size()-1U])
+                        macrocode += ' ';
                     macrocode += str;
                     if (Token::Match(tok, "%name% %name%|%num%") ||
                         Token::Match(tok, "%num% %name%") ||
                         Token::simpleMatch(tok, "> >"))
-                        macrocode += " ";
+                        macrocode += ' ';
                 }
             }
         }
diff --git a/test/testpreprocessor.cpp b/test/testpreprocessor.cpp
index 5ee9a6d88..2a976ecf4 100644
--- a/test/testpreprocessor.cpp
+++ b/test/testpreprocessor.cpp
@@ -184,6 +184,7 @@ private:
         TEST_CASE(macro_mismatch);
         TEST_CASE(macro_linenumbers);
         TEST_CASE(macro_nopar);
+        TEST_CASE(macro_incdec);  // separate ++ and -- with space when expanding such macro: '#define M(X)  A-X'
         TEST_CASE(macro_switchCase);
         TEST_CASE(macro_NULL); // skip #define NULL .. it is replaced in the tokenizer
         TEST_CASE(string1);
@@ -1950,6 +1951,13 @@ private:
         ASSERT_EQUALS("\n${ $NULL }\n", OurPreprocessor::expandMacros(filedata));
     }
 
+    void macro_incdec() const {
+        const char filedata[] = "#define M1(X) 1+X\n"
+                                "#define M2(X) 2-X\n"
+                                "M1(+1) M2(-1)\n";
+        ASSERT_EQUALS("\n\n$1+ +$1 $2- -$1\n", OurPreprocessor::expandMacros(filedata));
+    }
+
     void macro_switchCase() const {
         {
             // Make sure "case 2" doesn't become "case2"