diff --git a/Source/Core/Core/DSP/DSPAssembler.h b/Source/Core/Core/DSP/DSPAssembler.h
index 183a4ef7ae..1887de09e7 100644
--- a/Source/Core/Core/DSP/DSPAssembler.h
+++ b/Source/Core/Core/DSP/DSPAssembler.h
@@ -50,7 +50,7 @@ enum err_t
 class DSPAssembler
 {
 public:
-  DSPAssembler(const AssemblerSettings& settings);
+  explicit DSPAssembler(const AssemblerSettings& settings);
   ~DSPAssembler();
 
   // line_numbers is optional (and not yet implemented). It'll receieve a list of ints,