diff --git a/CMake/CatchMiscFunctions.cmake b/CMake/CatchMiscFunctions.cmake
index 44c87500..502994e3 100644
--- a/CMake/CatchMiscFunctions.cmake
+++ b/CMake/CatchMiscFunctions.cmake
@@ -53,6 +53,7 @@ function(add_warnings_to_targets targets)
           "-Wdangling"
           "-Wdeprecated"
           "-Wdeprecated-register"
+          "-Wdouble-promotion"
           "-Wexceptions"
           "-Wexit-time-destructors"
           "-Wextra"
diff --git a/src/catch2/catch_approx.cpp b/src/catch2/catch_approx.cpp
index 407586d1..7da83645 100644
--- a/src/catch2/catch_approx.cpp
+++ b/src/catch2/catch_approx.cpp
@@ -25,7 +25,7 @@ bool marginComparison(double lhs, double rhs, double margin) {
 namespace Catch {
 
     Approx::Approx ( double value )
-    :   m_epsilon( std::numeric_limits<float>::epsilon()*100. ),
+    :   m_epsilon( std::numeric_limits<float>::epsilon()*100.f ),
         m_margin( 0.0 ),
         m_scale( 0.0 ),
         m_value( value )
diff --git a/tests/SelfTest/UsageTests/Condition.tests.cpp b/tests/SelfTest/UsageTests/Condition.tests.cpp
index 211dd3b9..21c04a1a 100644
--- a/tests/SelfTest/UsageTests/Condition.tests.cpp
+++ b/tests/SelfTest/UsageTests/Condition.tests.cpp
@@ -136,7 +136,7 @@ TEST_CASE( "Ordering comparison checks that should succeed" )
 
     REQUIRE( data.float_nine_point_one > 9 );
     REQUIRE( data.float_nine_point_one < 10 );
-    REQUIRE( data.float_nine_point_one < 9.2 );
+    REQUIRE( data.float_nine_point_one < 9.2f );
 
     REQUIRE( data.str_hello <= "hello" );
     REQUIRE( data.str_hello >= "hello" );
@@ -163,7 +163,7 @@ TEST_CASE( "Ordering comparison checks that should fail", "[.][failing]" )
 
     CHECK( data.float_nine_point_one < 9 );
     CHECK( data.float_nine_point_one > 10 );
-    CHECK( data.float_nine_point_one > 9.2 );
+    CHECK( data.float_nine_point_one > 9.2f );
 
     CHECK( data.str_hello > "hello" );
     CHECK( data.str_hello < "hello" );