diff --git a/lib/preprocessor.cpp b/lib/preprocessor.cpp
index a5e97b205..a799b0f24 100644
--- a/lib/preprocessor.cpp
+++ b/lib/preprocessor.cpp
@@ -3158,6 +3158,13 @@ std::string Preprocessor::expandMacros(const std::string &code, std::string file
                                 (macrocode[i-1] != macroChar)) {
                                 macrocode.insert(i, 1U, macroChar);
                             }
+                            // 1e-7
+                            if (i+3 < macrocode.size()     &&
+                                std::isdigit(macrocode[i]) &&
+                                macrocode[i+1] == 'e'      &&
+                                macrocode[i+2] == '-'      &&
+                                std::isdigit(macrocode[i+3]))
+                                i += 3;
                         }
                     }
                     line.insert(pos1, macroChar + macrocode);
diff --git a/test/testpreprocessor.cpp b/test/testpreprocessor.cpp
index f68863f90..1fa844b43 100644
--- a/test/testpreprocessor.cpp
+++ b/test/testpreprocessor.cpp
@@ -183,6 +183,7 @@ private:
         TEST_CASE(macro_simple15);
         TEST_CASE(macro_simple16);  // #4703: Macro parameters not trimmed
         TEST_CASE(macro_simple17);  // #5074: isExpandedMacro not set
+        TEST_CASE(macro_simple18);  // (1e-7)
         TEST_CASE(macroInMacro1);
         TEST_CASE(macroInMacro2);
         TEST_CASE(macro_mismatch);
@@ -1977,6 +1978,12 @@ private:
         ASSERT_EQUALS("\n$123+$123", OurPreprocessor::expandMacros(filedata));
     }
 
+    void macro_simple18() {  // (1e-7)
+        const char filedata[] = "#define A (1e-7)\n"
+                                "a=A;";
+        ASSERT_EQUALS("\na=$($1e-7);", OurPreprocessor::expandMacros(filedata));
+    }
+
     void macroInMacro1() {
         {
             const char filedata[] = "#define A(m) long n = m; n++;\n"