diff --git a/tests/driver_dht/main.c b/tests/driver_dht/main.c
index 8f6e2d04335cf6715d9d6ee83511272f09ef4ab9..11fc17170753f19a7a7a4093cc791984883986ac 100644
--- a/tests/driver_dht/main.c
+++ b/tests/driver_dht/main.c
@@ -57,9 +57,9 @@ int main(void)
             continue;
         }
 
-        size_t n = fmt_s16_dfp(temp_s, temp, 1);
+        size_t n = fmt_s16_dfp(temp_s, temp, -1);
         temp_s[n] = '\0';
-        n = fmt_s16_dfp(hum_s, hum, 1);
+        n = fmt_s16_dfp(hum_s, hum, -1);
         hum_s[n] = '\0';
 
         printf("DHT values - temp: %s°C - relative humidity: %s%%\n",
diff --git a/tests/driver_hdc1000/main.c b/tests/driver_hdc1000/main.c
index 864024c4845dd40877ef444434cd7f8b15782823..03e268c3f7356501c19c4d5afef3ab2ee99ace2f 100644
--- a/tests/driver_hdc1000/main.c
+++ b/tests/driver_hdc1000/main.c
@@ -51,9 +51,9 @@ int main(void)
         size_t len;
         hdc1000_read(&dev, &temp, &hum);
 
-        len = fmt_s16_dfp(tstr, temp, 2);
+        len = fmt_s16_dfp(tstr, temp, -2);
         tstr[len] = '\0';
-        len = fmt_s16_dfp(hstr, hum, 2);
+        len = fmt_s16_dfp(hstr, hum, -2);
         hstr[len] = '\0';
         printf("Reading: T: %s °C  RH: %s %%\n", tstr, hstr);
 
diff --git a/tests/driver_lis2dh12/main.c b/tests/driver_lis2dh12/main.c
index 0f8721c61e5f62779d474620a7610df8a7723dfd..ad7255e739817d6a1781646a7b8b5d59f4268ec5 100644
--- a/tests/driver_lis2dh12/main.c
+++ b/tests/driver_lis2dh12/main.c
@@ -59,7 +59,7 @@ int main(void)
 
         /* format data */
         for (int i = 0; i < 3; i++) {
-            size_t len = fmt_s16_dfp(str_out[i], data[i], 3);
+            size_t len = fmt_s16_dfp(str_out[i], data[i], -3);
             str_out[i][len] = '\0';
         }