diff --git a/src/cc65/codegen.c b/src/cc65/codegen.c
index 7fe2c031a..7b436256a 100644
--- a/src/cc65/codegen.c
+++ b/src/cc65/codegen.c
@@ -35,7 +35,13 @@
 int oursp	= 0;
 
 /* Current segment */
-static enum { SEG_CODE, SEG_RODATA, SEG_DATA, SEG_BSS } CurSeg = SEG_CODE;
+static enum {
+    SEG_INV = -1,	/* Invalid segment */
+    SEG_CODE,
+    SEG_RODATA,
+    SEG_DATA,
+    SEG_BSS
+} CurSeg = SEG_CODE;
 
 /* Segment names */
 static char* SegmentNames [4];
@@ -173,7 +179,7 @@ void g_postamble (void)
 
 
 
-static void UseSeg (unsigned NewSeg)
+static void UseSeg (int NewSeg)
 /* Switch to a specific segment */
 {
     if (CurSeg != NewSeg) {
@@ -217,7 +223,7 @@ void g_usebss (void)
 
 
 
-void SegName (unsigned Seg, const char* Name)
+static void SegName (int Seg, const char* Name)
 /* Set the name of a segment */
 {
     /* Free the old name and set a new one */
@@ -228,7 +234,7 @@ void SegName (unsigned Seg, const char* Name)
      * with the new name.
      */
     if (Seg == CurSeg) {
-    	CurSeg = -1;	/* Invalidate */
+       	CurSeg = SEG_INV;	/* Invalidate */
 	UseSeg (Seg);
     }
 }
@@ -438,7 +444,7 @@ static int funcargs;
 
 
 void g_enter (unsigned flags, unsigned argsize)
-/* Function prologue */	      
+/* Function prologue */
 {
     if ((flags & CF_FIXARGC) != 0) {
 	/* Just remember the argument size for the leave */
@@ -2219,9 +2225,9 @@ void g_push (unsigned flags, unsigned long val)
      	} else {
 
      	    /* Handle as 16 bit value */
-     	    hi = val >> 8;
+     	    hi = (unsigned char) (val >> 8);
      	    if (val <= 7) {
-		AddCodeLine ("\tjsr\tpush%u", val);
+		AddCodeLine ("\tjsr\tpush%u", (unsigned) val);
      	    } else if (hi == 0 || hi == 0xFF) {
      	    	/* Use special function */
      	    	ldaconst (val);
diff --git a/src/cc65/include.c b/src/cc65/include.c
index e5d798e39..8f7a35942 100644
--- a/src/cc65/include.c
+++ b/src/cc65/include.c
@@ -73,7 +73,6 @@ static char* Find (const char* Path, const char* File)
  */
 {
     const char* P;
-    unsigned Count;
     int Max;
     char PathName [FILENAME_MAX];
 
@@ -92,7 +91,7 @@ static char* Find (const char* Path, const char* File)
     /* Start the search */
     while (*P) {
         /* Copy the next path element into the buffer */
-     	Count = 0;
+     	int Count = 0;
      	while (*P != '\0' && *P != ';' && Count < Max) {
      	    PathName [Count++] = *P++;
      	}
diff --git a/src/cc65/locals.c b/src/cc65/locals.c
index 63b6b8611..315194295 100644
--- a/src/cc65/locals.c
+++ b/src/cc65/locals.c
@@ -54,7 +54,7 @@
 
 /* Register variable management */
 unsigned MaxRegSpace 	      	= 6; 	/* Maximum space available */
-static int RegOffs     	       	= 0;	/* Offset into register space */
+static unsigned RegOffs 	= 0;	/* Offset into register space */
 static const SymEntry** RegSyms	= 0;    /* The register variables */
 static unsigned RegSymCount 	= 0;    /* Number of register variables */
 
@@ -407,7 +407,8 @@ void RestoreRegVars (int HaveResult)
  * the accumulator must be saved across the restore.
  */
 {
-    int I, J, Bytes, Offs;
+    unsigned I, J;
+    int Bytes, Offs;
 
     /* If we don't have register variables in this function, bail out early */
     if (RegSymCount == 0) {
@@ -465,5 +466,5 @@ void RestoreRegVars (int HaveResult)
     }
 }
 
-
+	
 
diff --git a/src/cc65/mem.c b/src/cc65/mem.c
index 72b2291cc..13e643b8a 100644
--- a/src/cc65/mem.c
+++ b/src/cc65/mem.c
@@ -26,7 +26,7 @@
 #include <string.h>
 #include <stdlib.h>
 #include <ctype.h>
-#ifdef __WATCOMC__
+#if defined(__WATCOMC__) || defined(_MSC_VER)
 #  include <malloc.h>
 #endif
 
diff --git a/src/cc65/pragma.c b/src/cc65/pragma.c
index 2a0f7460c..b1fbc1f40 100644
--- a/src/cc65/pragma.c
+++ b/src/cc65/pragma.c
@@ -106,7 +106,7 @@ static void FlagPragma (unsigned char* Flag)
     constexpr (&val);
 
     /* Store the value into the flag parameter */
-    *Flag = val.e_const;
+    *Flag = (val.e_const != 0);
 }
 
 
@@ -116,14 +116,14 @@ void DoPragma (void)
 {
     static const struct tok_elt Pragmas [] = {
       	{ 	"bssseg",       PR_BSSSEG	},
-       	{       "codeseg",  	PR_CODESEG	},
-      	{       "dataseg",  	PR_DATASEG	},
-       	{       "regvaraddr",	PR_REGVARADDR	},
-      	{       "rodataseg",	PR_RODATASEG	},
+       	{       "codeseg",    	PR_CODESEG	},
+      	{       "dataseg",    	PR_DATASEG	},
+       	{       "regvaraddr", 	PR_REGVARADDR	},
+      	{       "rodataseg",  	PR_RODATASEG	},
 	{	"signedchars",	PR_SIGNEDCHARS	},
 	{	"staticlocals",	PR_STATICLOCALS	},
       	{       "zpsym",       	PR_ZPSYM  	},
-      	{       0,     	   	PR_ILLEGAL	},
+      	{       0,     	      	PR_ILLEGAL	},
     };
 
     int Pragma;