diff --git a/Cargo.lock b/Cargo.lock
index eb0a4e63..6854c816 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -210,15 +210,6 @@ version = "0.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e3b5ca7a04898ad4bcd41c90c5285445ff5b791899bb1b0abdd2a2aa791211d7"
 
-[[package]]
-name = "byte-unit"
-version = "4.0.14"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "95ebf10dda65f19ff0f42ea15572a359ed60d7fc74fdc984d90310937be0014b"
-dependencies = [
- "utf8-width",
-]
-
 [[package]]
 name = "byteorder"
 version = "1.4.3"
@@ -231,6 +222,12 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c4872d67bab6358e59559027aa3b9157c53d9358c51423c17554809a8858e0f8"
 
+[[package]]
+name = "bytesize"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6c58ec36aac5066d5ca17df51b3e70279f5670a72102f5752cb7e7c856adfc70"
+
 [[package]]
 name = "cache-padded"
 version = "1.2.0"
@@ -2039,7 +2036,6 @@ name = "starship"
 version = "1.7.1"
 dependencies = [
  "ansi_term",
- "byte-unit",
  "chrono",
  "clap",
  "clap_complete",
@@ -2077,7 +2073,7 @@ dependencies = [
  "shell-words",
  "starship-battery",
  "strsim",
- "sys-info",
+ "systemstat",
  "tempfile",
  "terminal_size",
  "toml",
@@ -2154,13 +2150,17 @@ dependencies = [
 ]
 
 [[package]]
-name = "sys-info"
-version = "0.9.1"
+name = "systemstat"
+version = "0.1.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0b3a0d0aba8bf96a0e1ddfdc352fc53b3df7f39318c71854910c3c4b024ae52c"
+checksum = "5f5dc96f7634f46ac7e485b8c051f5b89ec8ee5cc023236dd12fe4ae2fb52f80"
 dependencies = [
- "cc",
+ "bytesize",
+ "chrono",
+ "lazy_static",
  "libc",
+ "nom 7.1.1",
+ "winapi",
 ]
 
 [[package]]
@@ -2444,12 +2444,6 @@ version = "2.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "68b90931029ab9b034b300b797048cf23723400aa757e8a2bfb9d748102f9821"
 
-[[package]]
-name = "utf8-width"
-version = "0.1.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5190c9442dcdaf0ddd50f37420417d219ae5261bbf5db120d0f9bab996c9cba1"
-
 [[package]]
 name = "utf8parse"
 version = "0.2.0"
diff --git a/Cargo.toml b/Cargo.toml
index b476cb5a..6dca70a3 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -36,7 +36,6 @@ notify = ["notify-rust"]
 
 [dependencies]
 ansi_term = "0.12.1"
-byte-unit = "4.0.14"
 chrono = "0.4.19"
 clap = { version = "3.1.18", features = ["derive", "cargo", "unicode"] }
 clap_complete = "3.1.4"
@@ -70,7 +69,7 @@ shadow-rs = "0.11.0"
 # see: https://github.com/svartalf/rust-battery/issues/33
 starship-battery = { version = "0.7.9", optional = true }
 strsim = "0.10.0"
-sys-info = "0.9.1"
+systemstat = "=0.1.11"
 terminal_size = "0.1.17"
 toml = { version = "0.5.9", features = ["preserve_order"] }
 toml_edit = "0.14.4"
diff --git a/src/modules/memory_usage.rs b/src/modules/memory_usage.rs
index 9aaee11f..56789ae9 100644
--- a/src/modules/memory_usage.rs
+++ b/src/modules/memory_usage.rs
@@ -1,23 +1,44 @@
-use byte_unit::{Byte, ByteUnit};
+use systemstat::{
+    data::{saturating_sub_bytes, ByteSize},
+    Platform, System,
+};
 
 use super::{Context, Module, ModuleConfig};
 
 use crate::configs::memory_usage::MemoryConfig;
 use crate::formatter::StringFormatter;
 
-fn format_kib(n_kib: u64) -> String {
-    let byte = Byte::from_unit(n_kib as f64, ByteUnit::KiB).unwrap_or_else(|_| Byte::from_bytes(0));
-    let mut display_bytes = byte.get_appropriate_unit(true).format(0);
-    display_bytes.retain(|c| c != ' ');
+// Display a `ByteSize` in a human readable format.
+fn display_bs(bs: ByteSize) -> String {
+    let mut display_bytes = bs.to_string_as(true);
+    let mut keep = true;
+    // Skip decimals and the space before the byte unit.
+    display_bytes.retain(|c| match c {
+        ' ' => {
+            keep = true;
+            false
+        }
+        '.' => {
+            keep = false;
+            false
+        }
+        _ => keep,
+    });
     display_bytes
 }
 
-fn format_pct(pct_number: f64) -> String {
-    format!("{:.0}%", pct_number)
+// Calculate the memory usage from total and free memory
+fn pct(total: ByteSize, free: ByteSize) -> f64 {
+    100.0 * saturating_sub_bytes(total, free).0 as f64 / total.0 as f64
 }
 
-fn format_usage_total(usage: u64, total: u64) -> String {
-    format!("{}/{}", format_kib(usage), format_kib(total))
+// Print usage string used/total
+fn format_usage_total(total: ByteSize, free: ByteSize) -> String {
+    format!(
+        "{}/{}",
+        display_bs(saturating_sub_bytes(total, free)),
+        display_bs(total)
+    )
 }
 
 /// Creates a module with system memory usage information
@@ -31,36 +52,37 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
         return None;
     }
 
-    let system = match sys_info::mem_info() {
-        Ok(info) => info,
-        Err(err) => {
-            log::warn!("Unable to access memory usage information:\n{}", err);
-            return None;
+    let system = System::new();
+
+    // `memory_and_swap` only works on platforms that have an implementation for swap memory
+    // But getting both together is faster on some platforms (Windows/Linux)
+    let (memory, swap) = match system.memory_and_swap() {
+        // Ignore swap if total is 0
+        Ok((mem, swap)) if swap.total.0 > 0 => (mem, Some(swap)),
+        Ok((mem, _)) => (mem, None),
+        Err(e) => {
+            log::debug!(
+                "Failed to retrieve both memory and swap, falling back to memory only: {}",
+                e
+            );
+            let mem = match system.memory() {
+                Ok(mem) => mem,
+                Err(e) => {
+                    log::warn!("Failed to retrieve memory: {}", e);
+                    return None;
+                }
+            };
+
+            (mem, None)
         }
     };
 
-    // avail includes reclaimable memory, but isn't supported on all platforms
-    let avail_memory_kib = match system.avail {
-        0 => system.free,
-        _ => system.avail,
-    };
-    let used_memory_kib = system.total.saturating_sub(avail_memory_kib);
-    let total_memory_kib = system.total;
-    let ram_used = (used_memory_kib as f64 / total_memory_kib as f64) * 100.;
-    let ram_pct = format_pct(ram_used);
+    let used_pct = pct(memory.total, memory.free);
 
-    let threshold = config.threshold;
-    if ram_used.round() < threshold as f64 {
+    if (used_pct.round() as i64) < config.threshold {
         return None;
     }
 
-    let ram = format_usage_total(used_memory_kib, total_memory_kib);
-    let total_swap_kib = system.swap_total;
-    let used_swap_kib = system.swap_total.saturating_sub(system.swap_free);
-    let percent_swap_used = (used_swap_kib as f64 / total_swap_kib as f64) * 100.;
-    let swap_pct = format_pct(percent_swap_used);
-    let swap = format_usage_total(used_swap_kib, total_swap_kib);
-
     let parsed = StringFormatter::new(config.format).and_then(|formatter| {
         formatter
             .map_meta(|var, _| match var {
@@ -72,11 +94,16 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
                 _ => None,
             })
             .map(|variable| match variable {
-                "ram" => Some(Ok(&ram)),
-                "ram_pct" => Some(Ok(&ram_pct)),
-                // swap only shown if there is swap on the system
-                "swap" if total_swap_kib > 0 => Some(Ok(&swap)),
-                "swap_pct" if total_swap_kib > 0 => Some(Ok(&swap_pct)),
+                "ram" => Some(Ok(format_usage_total(memory.total, memory.free))),
+                "ram_pct" => Some(Ok(format!("{:.0}%", used_pct))),
+                "swap" => Some(Ok(format_usage_total(
+                    swap.as_ref()?.total,
+                    swap.as_ref()?.free,
+                ))),
+                "swap_pct" => Some(Ok(format!(
+                    "{:.0}%",
+                    pct(swap.as_ref()?.total, swap.as_ref()?.free)
+                ))),
                 _ => None,
             })
             .parse(None, Some(context))
@@ -92,3 +119,71 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
 
     Some(module)
 }
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    use crate::test::ModuleRenderer;
+
+    #[test]
+    fn test_format_usage_total() {
+        assert_eq!(
+            format_usage_total(ByteSize(1024 * 1024 * 1024), ByteSize(1024 * 1024 * 1024)),
+            "0B/1GiB"
+        );
+        assert_eq!(
+            format_usage_total(
+                ByteSize(1024 * 1024 * 1024),
+                ByteSize(1024 * 1024 * 1024 / 2)
+            ),
+            "512MiB/1GiB"
+        );
+        assert_eq!(
+            format_usage_total(ByteSize(1024 * 1024 * 1024), ByteSize(0)),
+            "1GiB/1GiB"
+        );
+    }
+
+    #[test]
+    fn test_pct() {
+        assert_eq!(
+            pct(ByteSize(1024 * 1024 * 1024), ByteSize(1024 * 1024 * 1024)),
+            0.0
+        );
+        assert_eq!(
+            pct(
+                ByteSize(1024 * 1024 * 1024),
+                ByteSize(1024 * 1024 * 1024 / 2)
+            ),
+            50.0
+        );
+        assert_eq!(pct(ByteSize(1024 * 1024 * 1024), ByteSize(0)), 100.0);
+    }
+
+    #[test]
+    fn zero_threshold() {
+        let output = ModuleRenderer::new("memory_usage")
+            .config(toml::toml! {
+                [memory_usage]
+                disabled = false
+                threshold = 0
+            })
+            .collect();
+
+        assert!(output.is_some())
+    }
+
+    #[test]
+    fn impossible_threshold() {
+        let output = ModuleRenderer::new("memory_usage")
+            .config(toml::toml! {
+                [memory_usage]
+                disabled = false
+                threshold = 9999
+            })
+            .collect();
+
+        assert!(output.is_none())
+    }
+}