diff --git a/backend/dm200.c b/backend/dm200.c
index aef37f0a..99a56e0f 100644
--- a/backend/dm200.c
+++ b/backend/dm200.c
@@ -250,8 +250,9 @@ char ecc200encode(unsigned char *t, int tl, unsigned char *s, int sl,
 		case 't':	// Text
 		case 'x':	// X12
 			{
-				char out[6], p = 0;
-				const char *e,
+				char out[6];
+				int p = 0;
+				const char *e=0,
 				    *s2 = "!\"#$%&'()*+,-./:;<=>?@[\\]_",
 				    *s3 = 0;
 				if (newenc == 'c') {
@@ -264,6 +265,8 @@ char ecc200encode(unsigned char *t, int tl, unsigned char *s, int sl,
 				}
 				if (newenc == 'x')
 					e = " 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ\r*>";
+				if (!e)
+					break;
 				do {
 					unsigned char c = s[sp++];
 					char *w;
@@ -493,7 +496,7 @@ static char *encmake(int l, unsigned char *s, int *lenp, char exact)
 {
 	char *encoding = 0;
 	int p = l;
-	char e;
+	int e;
 	struct {
 		// number of bytes of source that can be encoded in a row at this point
 		// using this encoding mode
@@ -508,8 +511,8 @@ static char *encmake(int l, unsigned char *s, int *lenp, char exact)
 	if (l > MAXBARCODE)
 		return 0;	// not valid
 	while (p--) {
-		char b = 0, sub;
-		int sl, tl, bl, t;
+		char  sub;
+		int b = 0, sl, tl, bl, t;
 		// consider each encoding from this point
 		// ASCII
 		sl = tl = 1;
@@ -790,10 +793,9 @@ static char *encmake(int l, unsigned char *s, int *lenp, char exact)
 	encoding = safemalloc(l + 1);
 	p = 0;
 	{
-		char cur = E_ASCII;	// starts ASCII
+		int cur = E_ASCII;	// starts ASCII
 		while (p < l) {
-			int t, m = 0;
-			char b = 0;
+			int t, m = 0, b = 0;
 			for (e = 0; e < E_MAX; e++)
 				if (enc[p][e].t
 				    && ((t = enc[p][e].t + switchcost[cur][e]) <