diff --git a/src/api.cpp b/src/api.cpp
index 63e6500..abeb2ef 100644
--- a/src/api.cpp
+++ b/src/api.cpp
@@ -402,7 +402,9 @@ DK_API bool taskkill(DWORD identifier, KillMethod method) {
 
             if (process) {
                 // Bam, terminated!
-                TerminateProcess(process, -1);
+                TerminateProcess(process, static_cast<UINT>(-1));
+                // -1 is the exit code for the process - in this case,
+                // indicating internal failure.
                 CloseHandle(process);
                 return true;
             }
diff --git a/src/gui.cpp b/src/gui.cpp
index 4e9cb3f..ca1e518 100644
--- a/src/gui.cpp
+++ b/src/gui.cpp
@@ -54,14 +54,14 @@ const char* get_selected(HWND listbox) {
     Get the selected item in a listbox.
     */
 
-    int index = SendMessage(listbox, LB_GETCURSEL, 0, 0);
+    int index = static_cast<UINT>(SendMessage(listbox, LB_GETCURSEL, 0, 0));
     if (index == LB_ERR) {
         // Unable to get listbox contents for some reason (no selection?)
         return "";
     }
 
     // Needed to specify memory allocation
-    int length = SendMessage(listbox, LB_GETTEXTLEN, index, 0);
+    int length = static_cast<UINT>(SendMessage(listbox, LB_GETTEXTLEN, index, 0));
 
     // Create a character buffer to output the selected item
     char* buffer = new char[length + 1];
diff --git a/src/system.cpp b/src/system.cpp
index 305ccb4..e31fe0f 100644
--- a/src/system.cpp
+++ b/src/system.cpp
@@ -295,7 +295,7 @@ int ErrorBuffer::overflow(int c) {
         original_buffer->sputc('1');
         original_buffer->sputc('m');
 
-        original_buffer->sputc(c);
+        original_buffer->sputc(static_cast<_Elem>(c));
 
         original_buffer->sputc('\033');
         original_buffer->sputc('[');