diff --git a/lib/libc/musl/src/internal/floatscan.c b/lib/libc/musl/src/internal/floatscan.c
index 8c0828fcb39e6e0e742309913eef1aa955e582e5..b15366b685e9757d56b3c41d5caf7a69c4682d35 100644
--- a/lib/libc/musl/src/internal/floatscan.c
+++ b/lib/libc/musl/src/internal/floatscan.c
@@ -347,7 +347,7 @@ static long double hexfloat(FILE *f, int bits, int emin, int sign, int pok)
 			else d = c-'0';
 			if (dc<8) {
 				x = x*16 + d;
-			} else if (dc < LDBL_MANT_DIG/4+1) {
+			} else if (dc < (LDBL_MANT_DIG+3)/4+1) {
 				y += d*(scale/=16);
 			} else if (d && !gottail) {
 				y += 0.5*scale;
diff --git a/lib/libc/wasi/libc-top-half/musl/src/internal/floatscan.c b/lib/libc/wasi/libc-top-half/musl/src/internal/floatscan.c
index ec50fe0765046a04a8757bb7114f8ed530a6ed09..4cc6059f438e4368da315a13f12988f0ea1ec3f2 100644
--- a/lib/libc/wasi/libc-top-half/musl/src/internal/floatscan.c
+++ b/lib/libc/wasi/libc-top-half/musl/src/internal/floatscan.c
@@ -388,7 +388,7 @@ static long double hexfloat(FILE *f, int bits, int emin, int sign, int pok)
 			else d = c-'0';
 			if (dc<8) {
 				x = x*16 + d;
-			} else if (dc < LDBL_MANT_DIG/4+1) {
+			} else if (dc < (LDBL_MANT_DIG+3)/4+1) {
 				y += d*(scale/=16);
 			} else if (d && !gottail) {
 				y += 0.5*scale;