diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 973403f..c3a7327 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -98,11 +98,19 @@ else()
           $<$<CXX_COMPILER_VERSION:5.0.2>:-Wno-undefined-func-template>
         >
         $<$<CXX_COMPILER_ID:GNU>:
+          -Wdouble-promotion # float implicit to double
+          -Wlogical-op # suspicious uses of logical operators
           $<$<NOT:$<VERSION_LESS:$<CXX_COMPILER_VERSION>,6>>:
+            -Wduplicated-cond # duplicated if-else conditions
+            -Wmisleading-indentation
+            -Wnull-dereference
             $<$<EQUAL:${GSL_CXX_STANDARD},14>: # no support for [[maybe_unused]]
               -Wno-unused-variable
             >
           >
+          $<$<NOT:$<VERSION_LESS:$<CXX_COMPILER_VERSION>,7>>:
+            -Wduplicated-branches # identical if-else branches
+          >
         >
     )
 endif(MSVC)
@@ -194,6 +202,22 @@ else()
           -Wno-unknown-attributes
           -Wno-weak-vtables
         >
+        $<$<CXX_COMPILER_ID:GNU>:
+          -Wdouble-promotion # float implicit to double
+          -Wlogical-op # suspicious uses of logical operators
+          -Wuseless-cast # casting to its own type
+          $<$<NOT:$<VERSION_LESS:$<CXX_COMPILER_VERSION>,6>>:
+            -Wduplicated-cond # duplicated if-else conditions
+            -Wmisleading-indentation
+            -Wnull-dereference
+          >
+          $<$<NOT:$<VERSION_LESS:$<CXX_COMPILER_VERSION>,7>>:
+            -Wduplicated-branches # identical if-else branches
+          >
+          $<$<NOT:$<VERSION_LESS:$<CXX_COMPILER_VERSION>,8>>:
+            -Wcast-align=strict # increase alignment (i.e. char* to int*)
+          >
+        >
     )
 endif(MSVC)