diff --git a/src/emitter.c b/src/emitter.c
index 7b11fdc..fed51a2 100644
--- a/src/emitter.c
+++ b/src/emitter.c
@@ -101,7 +101,7 @@ static kdl_owned_string _float_to_string(double f, kdl_float_printing_options co
 
     bool negative = f < 0.0;
     f = fabs(f);
-    int exponent = (int)floor(log10(f));
+    int exponent = f != 0.0 ? (int)floor(log10(f)) : 0;
     double exp_factor = 1.0;
     if (abs(exponent) < opts->min_exponent) {
         // don't use scientific notation
diff --git a/src/tokenizer.c b/src/tokenizer.c
index b1df34f..10c57a6 100644
--- a/src/tokenizer.c
+++ b/src/tokenizer.c
@@ -96,7 +96,9 @@ static size_t _refill_tokenizer(kdl_tokenizer* self)
         self->document.len = 0;
     }
     // Move whatever data is left unparsed to the top of the buffer
-    memmove(self->buffer, self->document.data, self->document.len);
+    if (self->document.len > 0) {
+        memmove(self->buffer, self->document.data, self->document.len);
+    }
     self->document.data = self->buffer;
     size_t len_available = self->buffer_size - self->document.len;
     if (len_available < MIN_BUFFER_SIZE) {