diff --git a/src/Greenshot/Forms/ResizeSettingsForm.Designer.cs b/src/Greenshot/Forms/ResizeSettingsForm.Designer.cs
index 689fe263c..e2f9a6c74 100644
--- a/src/Greenshot/Forms/ResizeSettingsForm.Designer.cs
+++ b/src/Greenshot/Forms/ResizeSettingsForm.Designer.cs
@@ -19,6 +19,7 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
+using System.Windows.Forms;
 using Greenshot.Base.Controls;
 
 namespace Greenshot.Forms {
@@ -65,7 +66,7 @@ namespace Greenshot.Forms {
 			this.buttonOK.Size = new System.Drawing.Size(75, 23);
 			this.buttonOK.TabIndex = 6;
 			this.buttonOK.UseVisualStyleBackColor = true;
-			this.buttonOK.Click += new System.EventHandler(this.buttonOK_Click);
+			this.buttonOK.Click += new System.EventHandler(this.ButtonOK_Click);
 			// 
 			// buttonCancel
 			// 
@@ -108,8 +109,8 @@ namespace Greenshot.Forms {
 			this.textbox_height.Name = "textbox_height";
 			this.textbox_height.Size = new System.Drawing.Size(69, 20);
 			this.textbox_height.TabIndex = 3;
-			this.textbox_height.KeyUp += new System.Windows.Forms.KeyEventHandler(this.textbox_KeyUp);
-			this.textbox_height.Validating += new System.ComponentModel.CancelEventHandler(this.textbox_Validating);
+			this.textbox_height.KeyUp += new System.Windows.Forms.KeyEventHandler(this.Textbox_KeyUp);
+			this.textbox_height.Validating += new System.ComponentModel.CancelEventHandler(this.Textbox_Validating);
 			// 
 			// textbox_width
 			// 
@@ -117,8 +118,8 @@ namespace Greenshot.Forms {
 			this.textbox_width.Name = "textbox_width";
 			this.textbox_width.Size = new System.Drawing.Size(69, 20);
 			this.textbox_width.TabIndex = 1;
-			this.textbox_width.KeyUp += new System.Windows.Forms.KeyEventHandler(this.textbox_KeyUp);
-			this.textbox_width.Validating += new System.ComponentModel.CancelEventHandler(this.textbox_Validating);
+			this.textbox_width.KeyUp += new System.Windows.Forms.KeyEventHandler(this.Textbox_KeyUp);
+			this.textbox_width.Validating += new System.ComponentModel.CancelEventHandler(this.Textbox_Validating);
 			// 
 			// combobox_width
 			// 
@@ -127,19 +128,21 @@ namespace Greenshot.Forms {
 			this.combobox_width.Name = "combobox_width";
 			this.combobox_width.Size = new System.Drawing.Size(65, 21);
 			this.combobox_width.TabIndex = 2;
-			// 
-			// combobox_height
-			// 
-			this.combobox_height.FormattingEnabled = true;
+            this.combobox_width.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList;
+            // 
+            // combobox_height
+            // 
+            this.combobox_height.FormattingEnabled = true;
 			this.combobox_height.ItemHeight = 13;
 			this.combobox_height.Location = new System.Drawing.Point(165, 38);
 			this.combobox_height.Name = "combobox_height";
 			this.combobox_height.Size = new System.Drawing.Size(65, 21);
 			this.combobox_height.TabIndex = 4;
-			// 
-			// ResizeSettingsForm
-			// 
-			this.AcceptButton = this.buttonOK;
+            this.combobox_height.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList;
+            // 
+            // ResizeSettingsForm
+            // 
+            this.AcceptButton = this.buttonOK;
             this.AutoScaleDimensions = new System.Drawing.SizeF(96F, 96F);
             this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Dpi;
 			this.CancelButton = this.buttonCancel;
diff --git a/src/Greenshot/Forms/ResizeSettingsForm.cs b/src/Greenshot/Forms/ResizeSettingsForm.cs
index 06952272c..7ef60442d 100644
--- a/src/Greenshot/Forms/ResizeSettingsForm.cs
+++ b/src/Greenshot/Forms/ResizeSettingsForm.cs
@@ -53,15 +53,16 @@ namespace Greenshot.Forms
             textbox_height.Text = effect.Height.ToString();
             _newWidth = effect.Width;
             _newHeight = effect.Height;
-            combobox_width.SelectedIndexChanged += combobox_SelectedIndexChanged;
-            combobox_height.SelectedIndexChanged += combobox_SelectedIndexChanged;
+            combobox_width.SelectedIndexChanged += Combobox_SelectedIndexChanged;
+            combobox_height.SelectedIndexChanged += Combobox_SelectedIndexChanged;
 
             checkbox_aspectratio.Checked = effect.MaintainAspectRatio;
         }
 
-        private void buttonOK_Click(object sender, EventArgs e)
+        private void ButtonOK_Click(object sender, EventArgs e)
         {
-            if (_newWidth != _effect.Width || _newHeight != _effect.Height)
+            const double tolerance = 3 * double.Epsilon;
+            if (Math.Abs(_newWidth - _effect.Width) > tolerance || Math.Abs(_newHeight - _effect.Height) > tolerance)
             {
                 _effect.Width = (int) _newWidth;
                 _effect.Height = (int) _newHeight;
@@ -72,16 +73,17 @@ namespace Greenshot.Forms
 
         private static bool Validate(object sender)
         {
-            if (sender is TextBox textbox)
+            if (sender is not TextBox textBox)
             {
-                if (!double.TryParse(textbox.Text, out var numberEntered))
-                {
-                    textbox.BackColor = Color.Red;
-                    return false;
-                }
-
-                textbox.BackColor = Color.White;
+                return true;
             }
+            if (!double.TryParse(textBox.Text, out _))
+            {
+                textBox.BackColor = Color.Red;
+                return false;
+            }
+
+            textBox.BackColor = Color.White;
 
             return true;
         }
@@ -116,7 +118,7 @@ namespace Greenshot.Forms
             textbox_height.Text = ((int) displayValue).ToString();
         }
 
-        private void textbox_KeyUp(object sender, KeyEventArgs e)
+        private void Textbox_KeyUp(object sender, KeyEventArgs e)
         {
             if (!Validate(sender))
             {
@@ -186,7 +188,7 @@ namespace Greenshot.Forms
             }
         }
 
-        private void textbox_Validating(object sender, System.ComponentModel.CancelEventArgs e)
+        private void Textbox_Validating(object sender, System.ComponentModel.CancelEventArgs e)
         {
             Validate(sender);
         }
@@ -196,7 +198,7 @@ namespace Greenshot.Forms
         /// </summary>
         /// <param name="sender"></param>
         /// <param name="e"></param>
-        private void combobox_SelectedIndexChanged(object sender, EventArgs e)
+        private void Combobox_SelectedIndexChanged(object sender, EventArgs e)
         {
             if (Validate(textbox_width))
             {